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Department of Veterinary Medicine

Cambridge Veterinary School

Intervertebral disc disease in dogs

Intervertebral disc disease (IVDD) is known to have a lifetime prevalence of ~20% in the Miniature Dachshund, and is fatal in 25% of cases. There is a perception that dogs which are more severely affected require decompressive surgery to recover ambulation, and a small amount of evidence to support this. The severe clinical signs are distressing to owners and further compounded by high financial costs of cross sectional imaging and surgery. It is however known that some dogs will recover without the need for surgery, and in 2017 I carried out an extensive data mining exercise which showed that recovery rates of  dogs suffering from thoracoolumbar IVDD treated with medical therapy are similar to those following surgical management in all grades of severity except the most severely affected dogs (Freeman and Jeffery, JSAP 2017: 58, 199-204).

My first PhD student carried out a prospective study of dogs rendered non-ambulatory following suspected acute thoracolumbar IVDD and treated medically rather than surgically; these dogs receive an MRI scan to confirm diagnosis, followed by a second scan after three months of medical management. It is known that in some cases both in human and canine disc herniation the herniated material is removed by natural processes (Argent et al 2019) and we were able to document the frequency with which this occured as well as the recovery rate of these dogs. We were able to convincingly answer our primary question: Can dogs rendered non-ambulatory following acute compressive thoracolumbar intervertebral disc herniation recover ambulation without decompressive surgery? with an emphatic 'Yes', with our recovery rate being as good as that documented for surgical treatment. The answer to our secondary question: Is recovery of ambulation and/or speed of recovery associated with removal of extruded disc material from the vertebral canal? was a fairly convincing 'No', although we documented a significant reduction in spinal cord compression in  a majority of affected dogs.

Ultimately we were unable to provide an answer to the key question: In dogs suffering acute severe thoraclumbar IVDD, which cases genuinely require surgical treatment, and which may recover just as well with medical management, since in this cohort at least, almst all recovered with medical management alone.

There are many other unanswered questions surrounding the pathogenesis of intervertebral disc extrusion in dogs as well as humans.

Some of the key questions we have are:

  • Why should disc calcification lead to an increased risk of disc extrusion?
  • What is the mechanism of disc calcification?
  • Can the process of calcification (and therefore disc extrusin) be interrupted or stopped?
  • Whet is the true genetic basis of IVDD

Additional work being carried out currently by my second PhD student with the assistance of Jonathan Powell’s biominerals laboratory, Professor Rachel Oliver from the Dept of Materials Science and Metallurgy and Professor Melinda Duer from the Department of Chemistry (among others) is aimed at characterising the role of calcification in IVDD. We are able to compare the mineral analysis of extruded and non-extruded disc material. Our early results indicate, as expected, a very high level of calcium and phosphorous in extruded disc material removed from the vertebral canal of clinical cases, and we have now been able to establish the nature of this calcified material in both extruded and non-extruded discs. We are now attempting to determine biomechanical features of this material on a micro- and nanoscale using microindentation and atomic force microscopy, as well as elucidating some of the chemical pathways involved.

It has been demonstrated that  there is a genetic basis for IVDD in dogs, with the retrogene FGF4 on chromosome 12 being implicated. My latest PhD student is about to begin a project looking into the genetic basis of intervertebral disc disease, in collaboration with Cathryn Mellersh and the Kennel Club Genetics Centre. We have already carried out large breed surveys of the cocker spaniel and French bulldog looking at various lifestyle factors which might play a role in IVDD. We now aim to analyse this data and at the same time begin genetic analysis of affected ad unaffected dogs with the hope of identifiying further genetic tools which may enable selective breeding to reduce the incidence of IVDD.

Finally we are involved in a newly launched Kennel Club screening scheme for Dachshunds which provides guidelines for breeding based on the numbers of calcified discs identified by radiography. We are able to offer a CT scan alongside the radiographs, a much more sensitive modality for identification of disc calcification, with the aim of following these dogs and assessing their likelihood of suffering IVDH later in life.

In addition to this work, I am collaborating with bioengineers George Malliaras and Christopher Proctor, who have designed an electrical stimulation device intended to deliver an oscillating electrical field to injured spinal cord, as well as Ben Woodington whose work includes the development of micro-sensors capable of detecting electrical activity from deep within the brain. Thes projects have potential applications in both veterinary and human neurology and neurosurgery.


I graduated from Cambridge in 1987 and then spent 6 years in mixed practice in Yorkshire and Suffolk. In 1993 I gained the RCVS certificate in small animal orthopaedics, and went on to develop a referral centre for orthopaedics and neurology in my home county of Essex.

Following a 6 year non-conforming residency in neurology under the supervision of Nick Jeffery I attained the European Diploma in Veterinary Neurology in 2014, and in 2016 took up my current post as Principal Clinical Neurologist at the Queen's Veterinary School Hospital in the Department of Veterinary Medicine. The neurology service has grown rapidly over the last few years, and currently employs 5 specialist neurologists as well as 4 residents in training and a service nurse. My main areas of interest continue to be the management of canine spinal cord injury specifically intervertebral disc disease, and I have published widely on this topic in the last few years. Despite having a mainly clinical role I have been able to combine research and teaching interests, and the Cambridge Intervertebral Disc Disease research group now consists of 2 PhD students with multiple external collaborators.

I have lectured widely both nationally and internationally, and has published a textbook of clinical neurology aimed primarily at general practitioners and veterinary students A Practical Approach to Neurology for the Small Animal Practitioner | Wiley Online Books.  


My research is focused on intervertebral disc disease in dogs. Currently I have two PhD students: Viviana Rojas who is fully funded by the charity Dachshund Rescue UK, and Bruno Lopes who is part-funded by Dahshund Health UK (DHUK). Viviana is following on from a previous MPhil student Theresa Banu Yenen, investigating the mineral content of intervertebral discs and its role in the pathology of the disease, whilst Bruno will investiogate the genetic basis of the disease in collaboration with the Kennel Club Genetics Centre.

My first student Sam Khan completed his PhD funded by grants from the Kennel Club Charitable Trust and BSAVA Petsavers as well as DHUK.



Key publications: 

Formoso S, Khan S, Lowrie M, Hughes J, Freeman P. Interobserver agreement of computed tomography in detecting calcified intervertebral discs in comparison with radiography in a population of 13 healthy British Dachshund dogs. First published: 28 March 2023

Freeman P, Jeffery N. (2022). Is decompression in acute thoracolumbar intervertebral disc herniation overvalued? Front Vet Sci. 2022 Nov 9;9:1049366. doi: 10.3389/fvets.2022.1049366. PMID: 36439357; PMCID: PMC9682007.

Khan S, Freeman P. (2022). HASTE MRI sequence findings correlate with loss of deep pain perception in dogs with thoracolumbar disc extrusion. First published: 27 October 2022.

Peschard AL, Freeman P, Genain MA. (2022). Follow-up MRI appearance of the surgical site in dogs treated for thoracolumbar intervertebral disc herniation and showing ongoing or recurrent neurological symptoms. First published: 12 August 2022.

Khan S, Freeman P (2022). Bayesian clinical reasoning in the first opinion approach to a dog with suspected thoracolumbar pain. First published: 25 June 2022

Craciun I, Khan S, Hughes J, Freeman P (2022). Contrast-Enhanced Low-Field MRI Occasionally Alters the Surgical Approach for Canine Intervertebral Disc Extrusion. DO  - 10.1055/s-0042-1748877. Veterinary and Comparative Orthopaedics and Traumatology

Argent V, Perillo R, Jeffery N, Freeman P. (2022). Recurrence of signs consistent with cervical intervertebral disc extrusion in dogs. J Small Anim Pract. 2022 Feb 10. doi: 10.1111/jsap.13480. Epub ahead of print. PMID: 35146745.

Longo, S., Gomes, S. A., Briola, C., Duffy, K., Targett, M., Jeffery, N. D., & Freeman, P. (2021). Association of magnetic resonance assessed disc degeneration and late clinical recurrence in dogs treated surgically for thoracolumbar intervertebral disc extrusions. Journal of veterinary internal medicine35(1), 378–387.

Fox K, Fox J, Bexfield N, Freeman P. Computerised decision support in veterinary medicine, exemplified in a canine idiopathic epilepsy care pathway. J Small Anim Pract. 2021 Oct;62(10):911-917. doi: 10.1111/jsap.13345. Epub 2021 Jun 21. PMID: 34155645.

Hall JF, Freeman P. Approach to and Practice of Disc Fenestration in the Management of Intervertebral Disc Extrusions in Dogs: A Questionnaire Survey. Vet Comp Orthop Traumatol. 2021 Aug 3. doi: 10.1055/s-0041-1731809. Epub ahead of print. PMID: 34344052.

Freeman P, Jeffery ND. Re-opening the window on fenestration as a treatment for acute thoracolumbar intervertebral disc herniation in dogs. J Small Anim Pract. 2017 Apr;58(4):199-204. doi: 10.1111/jsap.12653. PMID: 28276121.

Jeffery ND, Freeman PM. The Role of Fenestration in Management of Type I Thoracolumbar Disk Degeneration. Vet Clin North Am Small Anim Pract. 2018 Jan;48(1):187-200. doi: 10.1016/j.cvsm.2017.08.012. Epub 2017 Oct 23. PMID: 29074336.

Harris G, Freeman P. Introduction of Disc Material into the Vertebral Canal by Fenestration of Thoracolumbar Discs Following Decompressive Surgery. Vet Comp Orthop Traumatol. 2020 Jan;33(1):66-70. doi: 10.1055/s-0039-1700554. Epub 2019 Nov 22. PMID: 31756749.

Hare C, Sanchini L, Worrall C, Van Poucke S, Alves L, Restif O, Freeman P. Rapid in-house method of CSF analysis utilising sedimentation direct from the spinal needle. J Small Anim Pract. 2019 Aug;60(8):486-492. doi: 10.1111/jsap.13010. Epub 2019 Apr 26. PMID: 31025384.

Freeman PM, Holmes MA, Jeffrey ND, Granger N. Time requirement and effect on owners of home-based management of dogs with severe chronic spinal cord injury.  Journal of Veterinary Behavior (2013), 8(6): 439-443

Other publications: 

Halstead S, Jackson M,….. Freeman P et al. (2022). Serum anti-GM2 and anti-GalNAc-GD1a ganglioside IgG antibodies are biomarkers for immune-mediated polyneuropathies in cats

First published: 27 December 2022


Dutil GF, Guevar J, … Freeman P et al. (2022). Otitis media and interna with or without polyps in cats: association between meningeal enhancement on postcontrast MRI, cerebrospinal fluid abnormalities, and clinician treatment choice and outcome. J Feline Med Surg. 2022 Dec;24(12):e481-e489. doi: 10.1177/1098612X221125573. Epub 2022 Nov 21.

Lopes B, … Freeman P et al. (2022). Cranial thoracic myelopathies (T1-T6 vertebrae): Retrospective evaluation of the signalment, clinical presentation, and, presumptive or final diagnoses in 84 dogs. Front Vet Sci. 2022 Sep 12;9:960912. doi: 10.3389/fvets.2022.960912.

Woodington B…. Freeman P et al. (2022). X-Ray Markers for Thin Film Implants. Advanced Healthcare Materials. First published: 23 July 2022

Padley H, Freeman P et al. (2022). Imaging characteristics of thoracolumbar spinal stenosis due to articular process hyperplasia and degenerative joint disease in six large breed dogs First published: 21 February 2022 Vet Rad and Ultrasound.

Walker PE, Freeman P, Monforte Monteiro SR, et al. (2022). Description of neurological mimics presented to the neurology service of a small animal referral hospital. The Veterinary Record. 2022 Jan:e1268. DOI: 10.1002/vetr.1268. PMID: 34993971.

Mavrides D, Charalambous M, Freeman P.(2021). Long-term follow-up of spinal segmental stabilization for surgical treatment of dorsal hemivertebrae associated with kyphosis in brachycephalic dogs. Can Vet J. 2021 Dec;62(12):1323-1327. PMID: 34857969; PMCID: PMC8591567

Monforte Monteiro SR et al, “Medical management of spinal epidural empyema in five dogs”. Journal of the American Veterinary Medicine Association (2017) 249, 10: 1180-1186.

Cashmore RG, Harcourt-Brown TR, Freeman PM, Jeffery ND, Granger N. Clinical diagnosis and treatment of suspected neuropathic pain in three dogs. Australian Veterinary Journal (2009), 87(1): 45-50.

Serrano G, Freeman P. Neosporosis presenting as temporal muscle atrophy in a dog. Veterinary Record Case Reports Mar 2017, 5 (1) e000380; DOI: 10.1136/vetreccr-2016-000380

Kortum A, Freeman P. Fibrocartilaginous embolism and marked cerebrospinal fluid pleocytosis in a dog. Veterinary Record Case Reports May 2018, 6 (2) e000608; DOI: 10.1136/vetreccr-2018-000608

Argent V, Fraser A, Alves L, Freeman P. Spontaneous regression of a cervical intervertebral disc extrusion in French bulldogs documented on MRI after medical management. Veterinary Record Case Reports Apr 2019, 7 (2) e000817; DOI: 10.1136/vetreccr-2019-000817

Clarke N, Harris G, Greville-Heygate O,Constantino-Casas F, Freeman P. Spinal cord clear cell meningioma in a dog. Veterinary Record Case Reports Jul 2020, 8 (3) e001118; DOI: 10.1136/vetreccr-2020-001118

Freeman P. Sacrococcygeal intervertebral disc extrusion in a Dachshund. Veterinary Record (2010), 167(16): 618-9

Freeman PM, Harcourt-Brown TR, Jeffery ND, Granger N. Electrophysiologic evidence of polyneuropathy in a cat with signs of bilateral brachial plexus neuropathy. J Am Vet Med Assoc. 2009 Jan 15;234(2):240-4. doi: 10.2460/javma.234.2.240. PMID: 19210244.

Teaching and Supervisions


Neurology module organiser, Cambridge University Veterinary School

Resident supervisor (Bruno Scalia and Dorothy Hadju)

Research supervision: 

Viviana Rojas (PhD)

Bruno Lopes (PhD)

Other Professional Activities

Principal Clinical Neurologist at Queen's Veterinary School Hospital

Principal Clinical Neurologist
European & RCVS Specialist in Veterinary Neurology
Teaching Professor of Neurology and Neurosurgery

Contact Details

Takes PhD students
Available for consultancy


Local Affiliations: 
Person keywords: 
Disc disease
Veterinary Education
Dachshund Rescue UK
The Alice Noakes Trust
The Debs Foundation
BSAVA Petsavers
Dachshund Health UK
Dachshund Rescue UK
Kennel Club Charitable Trust